Inbound Email Delivery Delays from Gmail

Posted at 2026-09-13T15:00:00Z

Summary

We are investigating reports of delayed inbound email delivery from Gmail senders. Purelymail’s gateway systems and mail services are operating normally and as designed. However, under high connection volumes, connections from Gmail IP pools triggered our automated IP rate limiting defenses at the network gateway, resulting in temporary connection deferrals.

Timeline

  • September 10, 2026: We suspect intermittent connection deferrals began occurring during peak traffic windows.
  • September 11 to 12, 2026: Purelymail received sporadic support reports of delayed emails from Gmail senders.
  • September 13, 2026 at 15:00 UTC: Our engineering team began an in-depth investigation and identified that legitimate Gmail mail server pools were hitting automated IP rate throttles.
  • Present: A configuration update is being prepared to explicitly exempt verified major email providers from IP connection rate limits.

Message Delivery & Retries

  • Emails are not lost: When a connection is temporarily deferred, standard SMTP protocols require the sending server (Gmail) to queue the message and retry delivery. Gmail will continually retry delivery over the coming hours until the email goes through.
  • Queued on Gmail’s side: Because deferred messages have not yet been accepted by Purelymail, the emails currently reside on Google’s sending servers and remain under Gmail’s delivery management.
  • Sender delay notices vs. bounces: During the retry period, Gmail may send the original sender an automated notification stating that delivery has been temporarily delayed. This is an informational warning, and Gmail is still actively trying to deliver the email. Only if Gmail completely exhausts its retry attempts will it issue a final “undeliverable” bounce notice to the sender, at which point the sender can try sending their email again.
  • Support visibility: Because rate limiting occurs at the initial IP connection level (before any sender or recipient information is transmitted), our servers do not know the intended recipient or message details. Consequently, Purelymail Support cannot view, track, or expedite delayed emails. Opening a support ticket will not speed up pending deliveries.

Next Steps

We are finalizing and deploying an update to add verified major provider ranges to our gateway whitelist. Once applied, deferred connections from Gmail will clear as Google’s retry cycles execute.